For nearly a decade, Michael Maurice Johnson dated the half-sister of Phylicia Barnes. He went along on family trips, and played basketball with their brother. He was like family, and considered Phylicia a "little sister," relatives say.

He was also the last person to see the girl alive in late December 2010. Now Baltimore prosecutors have charged him in the murder of the promising North Carolina teenager, whose nude body was found floating in the Susquehanna River one year ago this month.

In announcing the charge Thursday, authorities said very little about the case against Johnson, 28. He faces one count of first-degree murder, and officials declined to say how or where Phylicia was killed. Johnson was arrested late Wednesday outside his apartment after police said he tried to run from officers.

"This was an enormous collaborative effort by all agencies involved," Baltimore State's Attorney Gregg Bernstein said at a news conference, where he was flanked by city police and state troopers. "We hope it provides some measure of closure for the family."

Johnson, who does not appear to have a criminal record, had been repeatedly questioned since Phylicia's disappearance, but defense attorney Russell Neverdon said Johnson continues to deny any involvement. Neverdon briefly met with his client Thursday at the Baltimore City Detention Center.

"He told me, 'I'm innocent. I didn't do anything wrong. I will fight this to the very end,'" Neverdon said.

After 16 months of investigating, prosecutors obtained the grand jury indictment two days after the former lead detective in Baltimore, Daniel Nicholson IV, was suspended amid allegations that he conducted a rogue investigation to search for his own daughter. The teen went missing from Baltimore County last Friday and was later found unharmed.

Neverdon, during a news conference in his lower Charles Village office, said he believes that police expedited their case because of the troubles Nicholson faces, and that the single-count indictment shows their case remains circumstantial.

"Police had Mr. Johnson in their sights from the first day," Neverdon said, noting that his client met four times with homicide detectives and submitted a DNA sample for testing. Johnson's relatives were questioned and his car was searched, the lawyer said.

"The police made good on their promise," Neverdon said. "They told him during one meeting that it was only a matter of time before they got him."

Bernstein said Thursday that the allegations against Nicholson — whose squad attended the news conference without him — are a "completely separate matter" and will "absolutely not" impact the case against Johnson.

"If I thought for a moment that the alleged activity impacted the case, we wouldn't have brought it," Bernstein said.

Phylicia, an honor student who was set to graduate early from high school, vanished on Dec. 28, 2010, from the Reisterstown Road apartment of her half-sister Deena, while visiting from Monroe, N.C.

Deena has said she met Phylicia about 10 years ago at a family reunion in Baltimore, and they reconnected about three years ago on Facebook. Phylicia visited Baltimore several times, and hoped to attend Towson University.

Police have described the apartment as a "college house" that wasn't always secured and said that up to a dozen people were in and out of it over the holidays. Phylicia's mother, Janice Sallis-Mustafa, has accused the half-sister of condoning alcohol use and allowing men to come and go at the apartment.

On the day the teen disappeared, Johnson was moving out of Deena's apartment because the two of them had just broken up. Deena was at work, and Phylicia was asleep on the couch.

Johnson recalls her talking about leaving to get some food, Neverdon said.

The case attracted national attention, though not at first, and critics said the delay highlighted disparate interest from the media and authorities in cases where minority children go missing. In the initial days, police tried and failed to get the case on national news shows.

Meanwhile, city police poured unprecedented resources into the case, at one time involving half the homicide squad, and then forming a six-detective task force to lead the investigation. The FBI helped with helicopters that flew over city parks with heat sensors that could detect cadavers, and Maryland State Police joined in what authorities described as the most complex and largest missing persons cases in department history.

The Barnes family attended vigils to ensure authorities never forgot or gave up, as blogs lit up over rumors about the family and theories on the killing.

The wait for the arrest was very difficult, said Barnes' uncle, Harry Watson, who attended Thursday's news conference.

"Every day I got up with the same thing in mind: When will they make an arrest?" said Watson, 54, who lives in Catonsville. He wore a ribbon of purple, Phylicia's favorite color, and was joined by the teen's half-brother, Bryan, who wore a pendant with her photo — a gift, he said, from a stranger who took interest in the case.

The case sparked a measure in the Maryland legislature called "Phylicia's Law," which supporters say will improve coordination between law enforcement and community groups in missing-child cases.

Reached by phone, Phylicia's father, Russell Barnes, who first posted news of the arrest to Facebook, said the family was "rejoicing." He said he believes Phylicia's Law helped thrust the case back into the spotlight.

"No one [in Baltimore] knew Phylicia but the immediate family; [Johnson] dated Deena for over 10 years and Phylicia was part of his life," he said. "We will let the facts come out. Justice will be dealt with."

Legal experts said the single-count indictment was unusual, but they were unsure of the reasons behind it. Typically, associated charges such as manslaughter, assault, conspiracy or reckless endangerment are filed for authorities to fall back on if they cannot achieve a conviction on the murder count.

Glenn F. Ivey, the former top prosecutor in Prince George's County who is now in private practice and is not involved in the Barnes case, said Bernstein appeared to be keeping his options open for additional use of the grand jury.

Howard University Law School dean Kurt L. Schmoke, Baltimore's state's attorney from 1983 to 1987 and a former mayor, said in an e-mail that "one count is unusual. … I would have thought that more than one crime is involved."

Brian Thompson, a private defense attorney and former Baltimore County prosecutor, said a single-count indictment typically indicates that prosecutors are trying an "all-in" strategy on the most serious charge — which can be risky. "Typically with a single-count indictment, they're trying not to give the jury the opportunity to come up with some compromise verdict," he said.

Johnson was taken into custody late Wednesday after prosecutors obtained the indictment. Neverdon said his client suffered cuts and bruises, and had a bloody shirt, because a federal agent punched him and others kicked him during the arrest outside his apartment complex. Authorities said he was tackled after he tried to run and resisted arrest.

Neverdon said "it's strange how it all came about, the timing," indicating, he said, a rush to file charges. He said prosecutors couldn't suddenly have obtained any more evidence against Johnson than they have amassed over the past year.

"At best what they have is a circumstantial case," Neverdon said. He also suggested authorities were trying to stay ahead of the investigation of Nicholson, the detective.

Nicholson was charged in September in Baltimore County of assaulting his daughter by hitting her with a coaxial cable. He was upset about her using Facebook and talking to a boy, according to a county police report. The charges were dropped after the family agreed to attend counseling, but last Friday the daughter ran away from home after a dispute over grades and social networking, police say.

Nicholson allegedly searched a home in Northeast Baltimore while looking for his daughter; the occupants of the home reported to police that they were assaulted. The case is being investigated by the city Police Department's internal affairs division, with officials looking into whether detectives improperly tracked phones and used overtime funds, according to law enforcement sources.

If Nicholson went outside regulations to search for his own daughter, Neverdon said he will examine whether the detective broke the rules on the Barnes case as well. But authorities dismissed any such suggestion.

At one point in the case, an FBI agent filed search warrants seeking access to Johnson's Facebook account, among others, and several e-mail accounts that appeared to belong to Phylicia, with the search warrant referencing a child pornography investigation.

Authorities quickly sealed the warrants after they inadvertently became public, and it has not been explained how they related to the case.

On the one-year anniversary of her disappearance, Neverdon said investigators had "nothing" and were wasting time with Johnson. But he disclosed that the child pornography angle related to photos of Phylicia "streaking" with a group of people including Johnson, which he believes was being used to show his client was in the victim's small group of close friends.

Neverdon said Johnson and Phylicia shared a "big brother, big sister" relationship. Johnson had participated in family events and gatherings, he said, confirming relatives' accounts.

The defense attorney for 28-year-old Michael Johnson, charged with first-degree murder in the killing of Phylicia Barnes, told reporters on Thursday that his client had been struck and kicked during his arrest. He disputed a statement from the city's top prosecutor that the arrest went down...

The head of Baltimore's police union, Robert Cherry, launched a heartfelt defense of Det. Daniel T. Nicholson IV, who is suspended and accused of conducting an authorized raid while searching for his missing 15-year-old daughter:

Dec. 28, 2010 — Phylicia Barnes, visiting from Monroe, N.C., is last seen in her sister's apartment in the 6500 block of Eberle Drive, near the Reisterstown Road Metro station and shopping plaza. When her sister, Deena, can't locate her, family members call police. Deena's ex-boyfriend,...